Question

one word substitution - A number of horses driven together ....................​

Answer 1

A number of horses ridden together.

A herd of horses driven together.

Explanation:

• The word "driven" can be changed with the word "ridden".

• As the horses are ridden not driven by human beings so "ridden" is a better suitable verb instead of driven.

• Another word that we can change in the given sentence is the "number of horses".

• We can change it with the "herd" i.e. "a herd of horses" which makes total sense as herd is a group of animals.